Percussion mechanism for tools



P 29, 1931- G. H. THOMPSON 1,324,935

PERCUSSION MECHANISM FOR TOOLS Filed March 30, 1928 3 Sheets-Sheet lFIGI FIGZ m-um 3 Sept. 29, 1931. G. H. THOMPSON PERCUSSION MECHANISM FORTOOLS Filed March '30, 1928 3 Sheets-Sheet 2 Sept. 29. 1931'.

PERCUSSION MECHANISM FOR TOOLS G, H. THOMPSON 1,824,935

Filed March 50, 1928 5 Sheets-Sheet I5 FIG. 6 4

IN vE/v7- Patented Sept. 29, 1931 A NT OFFICE GEORGE Jimm wnpmzsolwor,snLLY on, BIRMINGHAM, Enemy];

- frmoussmli mcn lsm QB TOOLS Application filedmarcil 1928,, swarm.265,935,-;and.1n r at Britain x 31, 1927. This invention elates toimprovements in percussion mechanism for usej'in: percussion hand orother too ls,"sueh ias'aoi'ripping bride scaling tools, rivetingtools,c0ncriete;bnekers; road-breakers, coefl euttens; ieo'alhbonis,

and the like. ln suoh tooi'gftheiperopsion aetionof the-operutiwe'hwdorrdii'iil lgiusuafly p reduced byon' or moi'epereussiion members carriedby a body or cagefwuhieh 1a at'a'hi-ghspeed; the iereuss'ion membemibingiiree -to' fly goutwii rdly undemeentrifugail plane f thea-Xisofrotation. u

Figure12 isia longitudinal section in a plane at right ang'lesto the.axis of rotation; .1. Figure Bids a' seot-ionsimiiar to thatiof-Ei e-1' une @"butishow-ing the user-of two percussion baHs.1:2-W..; 1;; b 1'f e iiiguneiiAizisna-l similar, 'seotion :showing .221:modifiediamra-n'gement ofmhe-JoaHs.

through 1.31 inomplefie tool w emhody force as thebody ores'vgwrotmteslo nd to stnike the @pemuye 1183a or a: gssoo' ated theme Considerabledifiieuity n signing and manuiaotui'i gjpercussion :yneeh anisin *wh igh,w il-i 3ta nd up to the heavyi stressesj invdived' without xfifikage-orfzwpiil wea'r, u&11 whib11 gailgfie same v time-oun beprodueed nta -regeongible eost fl 1901612 The ob-jeot of my invention is to -provide impro-ved meehalniem 'wli'ih 1% ecsoiiomicaiutp produce and inwhihuhe weighp'obxhe {$0 tzmfy fpaiits othei -the pei ous's ion inem "be: ormembers is ai minimum that the stresses are orresponfiingily ediieedifMy improved meehanism filso lendsgteelf ate very accurate manning: u dbaianein i therotating'pnnts toreduee ear m "I-n percussionmeehanismueeeordi g' to invention pereusiibn 'inem'bers' in the of solidbells are ifilyfiuiitd: in "radial oyiindficzfl bore-s in an waifirl'iioh is rotated thi ough suitdblegeuning b eny eev ninpower-driving means ana tmi me power may eonvenientl y' be Veyd jtojfliemeciizinisin by'ia fixibie shafit f-hi body" M rotates --'the baills"'it l=e thn(kwn outwgiuly in is their bores and are edafited tojstiikehe n"-* ner end ofgthe tool of 11 gliding fzlfiirgef engaging the tool;the tbdi in "Ringer referably offset n om the n x-is bn'd x 'q so thatthebfliows' ap tflied l '2 i plunger may be as nee y-ngiial as "801116pl aot'ieailf "fl et-per us'si 4 nis'in in aoooL'da-nce with invent-10illustrated in the aeeolnfmnying di'aiyingsinl wh iohz* 1 reoives theFigure 1 is a longitudinal sectio tii'io w msm.

aoat -'Eigu1' :5 but embodying the :percus:

npenieneedinde- H I b I smn mechanism illustrated an :Figures 1 511612;

nnthe ,hdllOW! egy-lindrio a-L steel tube but is :p rlezfer ably;

eiirly when ifinishedn'by a moi which leaves inn 1 keyediiinsenibledin"ita'p er. :piniior: thnoughith'e" ibodiy and plug; the plug '6 mayvbelockedabyaa' setiscr ew;

ilihmplugfi has an iinwandiy pmj eotingz-ne-p r st xc'ainnoti move tinwandly I tfiir ibald' lFo ousl lion Zthe in wa'rd movement 1 of the 7 3ranged 'in fihe annular space 5 is: aiilongitndina'l mertieal: sectioning at simpiifiedxform of ipenoussion mechm "Figure oiisla ieiiiflliibiithtebibn the 115$ inwardly projecting flange 4 ialroundwi'cen having substantially the same contour 'as the baillfori'jvhiohififornis zn stop; f Screwed into th'e'zopeniendioif thezbdreis ailplug I6 whioh 'ris sition after-the mechanism jiSfiaS-T E; key-:7driven Alternatiyely the ba'lliand form a stop for its in-ward lnozvpxmenu The length of thiQ-xbossds suchwthmt under rebound: or whenthef'mcimr F fmiits eentneiof 5. gravity ito :passathe t and the man-v;muet always be th own outvva vd lyabyeentnirtg I ugSHforcLe-ftoWaBdSthesame'endmf the body;

one form ;0f'percussion mechanismin ithe :In the;menhanie1niil'lustnated; inliigultessli and 2 l'iijSlEEjPQIGliSSiQH memberiin-.,tiie-rfqimr of a E'sohd isteei hazli whieh lis'fireely mounted #10housing 1.0;; =:body:=;3.; This body; anny I be ins. unach-ined 1 from;T the" solid? aiEhebodylis :bonedfiom one: end a fthi oughstotheother.-.end,;and-?the under rebound :a' coiled spning (9 may Hoe are?b'etween the boss 8 end-the iotidzyflshelend ofithe :spni ng iwshien8111 -fi o'j cfii-Ikg a lsho'rit; distance beyond theendaof theuboss.Ari aziialihnle 1M portions of a cylindrical surface havingficlief disc,the periphery of the opening being of complementary form: In either casethe plug; has an integralaxial rod-23xwhich passes:

ball bearing in a suitable casing'and one trunnlon has-ascrewedextenslon15 to rece vea gear wheel or the like for driving the body.

' The centralpart ofthebody is preferably I formed with a thickenedbandTrIQ a-hd'flat bosses'are machined on this band' around. the holesfor the trunni'onscto form'cabutm'ents againstiwhi'ch thetrunnions arewelded. T

.The' ends of the body are machinedito 'form same'ax-isa's the axis ofroa'tion ofthe body, as shown 1n Figure '2,and'thlszmachnnng .and thefinal machiningofitlie trunnions are preferably eifected'aft'er th'etrunni'ons'g have been secured imp-lace to ensureperfect symmetry andtruth of the rotating parts.

beyond the p'eripheralsurface of the end'of thebody, and a groove 17'is-I nachin ed in each end of the body for the'passa'g'e of'th'e endiofa reciprocatingplunger orof the drill or" other tool which projectsinwardly from acasing sufficiently far to 'beengaged by the balloniea'chrevolution "of the body. .'Alter- -natively"the tt'hickness of theflange 4"n'1'ay be reduced so that the ball project's beyond-th'e-:periphery of the body and the groove 17: can

' f and the housingpfor the inner'end of the thenzbe omitted- "if i Inthe modification illustrated in Figure 3,tw o -balls 1, 1 are freelymounted'in oppo' site ends ofra hollow cylindrical body 18 at- .each'end'of which is a'cur ed'inwardlyproe jecting flange 19correspo'ndingto the flange 4." To permitofthefmachining of the in terior ofthe body.and of the inner-faces of the flanges 19 'the'body-ismade in'gtwo parts,

one end 20 being screwed :or forced on tothe main-part of the'body. Thejunctionis subsequentl y' Weldedf as shown at 2-1 to prevent parts may;

anyrisk of unscrewing, or the-two be lockedcby a'k'ey orset-pin;

For 'theinsertion and removal-of,- thef 1 a-clearance 0 ening i's-formedin the'".-side=-ofthe; body at't emiddle of its length, and is normallyclosed":by' a -remova-b'leplug 22.

This plug may be screwed into the opening as shown or it may'beaste'ppedor'coned diametrically 'through-the-bo'dy, and its ex tremity is:screw-threaded E to Treceive fag-nut.

whichmay be aplain cylindrical hole 26.

in fi oareduce the irietionalgrip of thespring 25 on the balls andtoallow them to turn freely: a pressure disc 05 ;or plate may beinterposedbetwieen thejball's andthe ends of the" springs as, shownatone end of the spring inFigure'4;-

lhe trunnionbearings for the mechanisms illustratedgin- Figures 3Vand 4are identical with thos'e"dscribed for the mechanisms illustratedin' Fiures -1 and 2and need not be furtherfde'scribed. V f

The'incorporat-ionvof; my improved percussionimecha'nism in a chippingor like percus'sion .toolis illustratedin Figures "5 and '6.

p Themechanism-is rotatablymounted in ball PIn themechanismillustrated:tlie ba'll at. the "outer end of" its travel doesnot proj'ect" with a bevel'wheel 29a driven by a flexible shaft 30sovthatthepercussion mechanism is continuously'rotate'd. =2The bevelwheel 29 flexible shaft are located; in a subsidiary casingwhichisrotatable'upon the main casing about the axis-of the-percussionmechanism so that the flexible shaft can be set at any angle tothecasingtofac'ilitate the handling ofthe tool ina-restricted space.

fAt -one point there projects through the casing and int'ofthe path ofthe ball or balls of; the percussionv mechanism the inner end of'asliding-piston or plunger 3liwhich receives a blowfrom theiball or ballson each revolution r The axis of the plunger 31 is offset from-the axisofthe percussion mechanismas shown in'F-igure 5 so that the blowis-applied'by' the ball tothe plunger in a dimotion as near-1y axial aspossible. The plungenis slidably guided in a cylindrical extension 32-ofthe casing and the chipping or othertool 33 is slidablyguidedfin theouter endofethisf.extension,.the inner end of the tool.ab11ttingagainst-'theouter end of the plunger so that'the plungertransmits to the tool the blows received from the percussion eg a iwz-wa1; 11.,

In the percussion mechanism illustrated in Figure 5 an extremely simpleconstruction is employed. A percussion ball 34 is freely mounted in acylindrical recess 35 drilled radially in a solid body 36 which issecured upon a rotatable spindle 37. A hole38 is drilled diametricallythrough the body from the bottom of the recess to prevent the movementof the ball from being retarded byair pressure behind it.

As the body rotates the ball is thrown outwardly by centrifugal forceand travels in agroove 39 of curved cross-section formed in the innerface of an annular liner 40 of hardened steel secured in the casingaround the body, and the inner end of the plunger 31 Only one ball hasbeen shown in Figure 5 but obviously two or more balls may be employedby providing a suitable number of radial recesses in the body to housethe balls.

I claim 1. Centrifugal percussion mechanism for percussion toolscomprising a casing, a body rotatably mounted in the casing, astationary ring surrounding said body, an annular groove of curvedcross-section in the inner face of the ring, a slidablymounted offsetstriker projecting through the ring, a radial cylindrical bore inthebody, and a ball member freely mounted in the bore, said ball memberwhen thrown outwardly by centrifugal force being adapted to travelaround the groove in the ring and to engage the end of the striker.

r 2. Centrifugal percussion mechanism for percussion tools comprising acasing, a rotatable body, a radial, cylindrical bore in the body, a ballmember freely mounted in the bore, and an inwardly projecting flange atthe outer end of the bore to form a, stop for the ball member, the innercontour of the flange conforming substantially with that of the ball,the body being provided with means for introducing the ball laterallyinto the bore.

3. Centrifugal percussion mechanism for percussion tools comprising acasing, a rotatable, tubular, cylindrical body, bearings for the body atright angles to its longitudinal axis, a plurality of ball membersfreely mounted in the tubular body, a unitary, re-. silient stopinterposed between the balls in the tubular body to limit the movementof the ball members inwardly within the body, and means for introducingthe balls and stop in the bore.

4. Centrifugal percussion mechanism for percussion tools comprising acasing, a robody constituting means for the insertion and removal of theball member.

5. Centrifugal percussion mechanism for percussion tools comprising acasing, a body rotatably mounted in the casing, a radial,

cylindrical bore in the body, a ball member freely mounted in the bore,the body being provided with a stop to prevent the outward escape of theball from the bore, and with readily removable means for permitting theremoval or the insertion of the ball behind the stop, and anofl'setstriker member slidably mounted in the casing and projecting into thepath of the ball member.

6. Centrifugal percussion mechanism for percussion tools comprising acasing, a rotatable body, a radial, cylindrical bore in the body, aballmember freely mounted in the bore, the body being provided with stops,to limit the movement of the ball member in both directions within thebore, and with readily removable means for permitting the removal or theinsertion of the ball between the stops, and bearings for the body atright angles to the longitudinal axis of the bore.

7 Centrifugal percussion mechanism for percussion tools comprising acasing, a rotatable body, a radial, cylindrical bore in the body, aballmember freely mounted in the bore, the body being provided with a stopto arrest the outwardmovement of the ball member and with a stop toarrest the inward movement of the, ball member towards the axis ofrotation of the body, so that'the centre of gravity of the ball membercannot pass that axis, and with readily removable means for insertingthe ball between the stops.

8. Centrifugal percussion mechanism for percussion tools comprising acasing, a rotatable body, a radial, cylindrical bore in the body, a ballmember freely mounted in the bore, a resilient stop in the bore behindthe ball member to cushion its rebound, and readily movable means forintroducing the resilient means and the ball into the bore.

. In testimony whereof I affix my signature.

GEORGE HENRY THOMPSON.

